1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Operations and constants for 32-bits floats (`f32` type)
13 #[allow(missing_doc)];
19 use from_str::FromStr;
20 use libc::{c_float, c_int};
21 use num::{FPCategory, FPNaN, FPInfinite , FPZero, FPSubnormal, FPNormal};
22 use num::{Zero, One, Bounded, strconv};
26 macro_rules! delegate(
31 $arg:ident : $arg_ty:ty
33 ) -> $rv:ty = $bound_name:path
38 pub fn $name($( $arg : $arg_ty ),*) -> $rv {
40 $bound_name($( $arg ),*)
49 fn sqrt(n: f32) -> f32 = intrinsics::sqrtf32,
50 fn powi(n: f32, e: i32) -> f32 = intrinsics::powif32,
51 fn sin(n: f32) -> f32 = intrinsics::sinf32,
52 fn cos(n: f32) -> f32 = intrinsics::cosf32,
53 fn pow(n: f32, e: f32) -> f32 = intrinsics::powf32,
54 fn exp(n: f32) -> f32 = intrinsics::expf32,
55 fn exp2(n: f32) -> f32 = intrinsics::exp2f32,
56 fn ln(n: f32) -> f32 = intrinsics::logf32,
57 fn log10(n: f32) -> f32 = intrinsics::log10f32,
58 fn log2(n: f32) -> f32 = intrinsics::log2f32,
59 fn mul_add(a: f32, b: f32, c: f32) -> f32 = intrinsics::fmaf32,
60 fn abs(n: f32) -> f32 = intrinsics::fabsf32,
61 fn copysign(x: f32, y: f32) -> f32 = intrinsics::copysignf32,
62 fn floor(x: f32) -> f32 = intrinsics::floorf32,
63 fn ceil(n: f32) -> f32 = intrinsics::ceilf32,
64 fn trunc(n: f32) -> f32 = intrinsics::truncf32,
65 fn rint(n: f32) -> f32 = intrinsics::rintf32,
66 fn nearbyint(n: f32) -> f32 = intrinsics::nearbyintf32,
67 fn round(n: f32) -> f32 = intrinsics::roundf32,
70 fn acos(n: c_float) -> c_float = cmath::c_float::acos,
71 fn asin(n: c_float) -> c_float = cmath::c_float::asin,
72 fn atan(n: c_float) -> c_float = cmath::c_float::atan,
73 fn atan2(a: c_float, b: c_float) -> c_float = cmath::c_float::atan2,
74 fn cbrt(n: c_float) -> c_float = cmath::c_float::cbrt,
75 fn cosh(n: c_float) -> c_float = cmath::c_float::cosh,
76 // fn erf(n: c_float) -> c_float = cmath::c_float::erf,
77 // fn erfc(n: c_float) -> c_float = cmath::c_float::erfc,
78 fn exp_m1(n: c_float) -> c_float = cmath::c_float::exp_m1,
79 fn abs_sub(a: c_float, b: c_float) -> c_float = cmath::c_float::abs_sub,
80 fn next_after(x: c_float, y: c_float) -> c_float = cmath::c_float::next_after,
81 fn frexp(n: c_float, value: &mut c_int) -> c_float = cmath::c_float::frexp,
82 fn hypot(x: c_float, y: c_float) -> c_float = cmath::c_float::hypot,
83 fn ldexp(x: c_float, n: c_int) -> c_float = cmath::c_float::ldexp,
84 // fn log_radix(n: c_float) -> c_float = cmath::c_float::log_radix,
85 fn ln_1p(n: c_float) -> c_float = cmath::c_float::ln_1p,
86 // fn ilog_radix(n: c_float) -> c_int = cmath::c_float::ilog_radix,
87 // fn modf(n: c_float, iptr: &mut c_float) -> c_float = cmath::c_float::modf,
88 // fn ldexp_radix(n: c_float, i: c_int) -> c_float = cmath::c_float::ldexp_radix,
89 fn sinh(n: c_float) -> c_float = cmath::c_float::sinh,
90 fn tan(n: c_float) -> c_float = cmath::c_float::tan,
91 fn tanh(n: c_float) -> c_float = cmath::c_float::tanh
94 // FIXME(#11621): These constants should be deprecated once CTFE is implemented
95 // in favour of calling their respective functions in `Bounded` and `Float`.
97 pub static RADIX: uint = 2u;
99 pub static MANTISSA_DIGITS: uint = 53u;
100 pub static DIGITS: uint = 15u;
102 pub static EPSILON: f64 = 2.220446e-16_f64;
104 // FIXME (#1433): this is wrong, replace with hexadecimal (%a) statics
106 pub static MIN_VALUE: f64 = 2.225074e-308_f64;
107 pub static MAX_VALUE: f64 = 1.797693e+308_f64;
109 pub static MIN_EXP: uint = -1021u;
110 pub static MAX_EXP: uint = 1024u;
112 pub static MIN_10_EXP: int = -307;
113 pub static MAX_10_EXP: int = 308;
115 pub static NAN: f32 = 0.0_f32/0.0_f32;
116 pub static INFINITY: f32 = 1.0_f32/0.0_f32;
117 pub static NEG_INFINITY: f32 = -1.0_f32/0.0_f32;
119 /// Various useful constants.
121 // FIXME (requires Issue #1433 to fix): replace with mathematical
122 // staticants from cmath.
124 // FIXME(#11621): These constants should be deprecated once CTFE is
125 // implemented in favour of calling their respective functions in `Float`.
127 /// Archimedes' constant
128 pub static PI: f32 = 3.14159265358979323846264338327950288_f32;
131 pub static FRAC_PI_2: f32 = 1.57079632679489661923132169163975144_f32;
134 pub static FRAC_PI_4: f32 = 0.785398163397448309615660845819875721_f32;
137 pub static FRAC_1_PI: f32 = 0.318309886183790671537767526745028724_f32;
140 pub static FRAC_2_PI: f32 = 0.636619772367581343075535053490057448_f32;
143 pub static FRAC_2_SQRTPI: f32 = 1.12837916709551257389615890312154517_f32;
146 pub static SQRT2: f32 = 1.41421356237309504880168872420969808_f32;
149 pub static FRAC_1_SQRT2: f32 = 0.707106781186547524400844362104849039_f32;
152 pub static E: f32 = 2.71828182845904523536028747135266250_f32;
155 pub static LOG2_E: f32 = 1.44269504088896340735992468100189214_f32;
158 pub static LOG10_E: f32 = 0.434294481903251827651128918916605082_f32;
161 pub static LN_2: f32 = 0.693147180559945309417232121458176568_f32;
164 pub static LN_10: f32 = 2.30258509299404568401799145468436421_f32;
172 fn eq(&self, other: &f32) -> bool { (*self) == (*other) }
178 fn lt(&self, other: &f32) -> bool { (*self) < (*other) }
180 fn le(&self, other: &f32) -> bool { (*self) <= (*other) }
182 fn ge(&self, other: &f32) -> bool { (*self) >= (*other) }
184 fn gt(&self, other: &f32) -> bool { (*self) > (*other) }
187 impl Default for f32 {
189 fn default() -> f32 { 0.0 }
194 fn zero() -> f32 { 0.0 }
196 /// Returns true if the number is equal to either `0.0` or `-0.0`
198 fn is_zero(&self) -> bool { *self == 0.0 || *self == -0.0 }
203 fn one() -> f32 { 1.0 }
207 impl Add<f32,f32> for f32 {
209 fn add(&self, other: &f32) -> f32 { *self + *other }
213 impl Sub<f32,f32> for f32 {
215 fn sub(&self, other: &f32) -> f32 { *self - *other }
219 impl Mul<f32,f32> for f32 {
221 fn mul(&self, other: &f32) -> f32 { *self * *other }
225 impl Div<f32,f32> for f32 {
227 fn div(&self, other: &f32) -> f32 { *self / *other }
231 impl Rem<f32,f32> for f32 {
233 fn rem(&self, other: &f32) -> f32 { *self % *other }
237 impl Neg<f32> for f32 {
239 fn neg(&self) -> f32 { -*self }
242 impl Signed for f32 {
243 /// Computes the absolute value. Returns `NAN` if the number is `NAN`.
245 fn abs(&self) -> f32 { abs(*self) }
247 /// The positive difference of two numbers. Returns `0.0` if the number is less than or
248 /// equal to `other`, otherwise the difference between`self` and `other` is returned.
250 fn abs_sub(&self, other: &f32) -> f32 { abs_sub(*self, *other) }
254 /// - `1.0` if the number is positive, `+0.0` or `INFINITY`
255 /// - `-1.0` if the number is negative, `-0.0` or `NEG_INFINITY`
256 /// - `NAN` if the number is NaN
258 fn signum(&self) -> f32 {
259 if self.is_nan() { NAN } else { copysign(1.0, *self) }
262 /// Returns `true` if the number is positive, including `+0.0` and `INFINITY`
264 fn is_positive(&self) -> bool { *self > 0.0 || (1.0 / *self) == INFINITY }
266 /// Returns `true` if the number is negative, including `-0.0` and `NEG_INFINITY`
268 fn is_negative(&self) -> bool { *self < 0.0 || (1.0 / *self) == NEG_INFINITY }
272 /// Round half-way cases toward `NEG_INFINITY`
274 fn floor(&self) -> f32 { floor(*self) }
276 /// Round half-way cases toward `INFINITY`
278 fn ceil(&self) -> f32 { ceil(*self) }
280 /// Round half-way cases away from `0.0`
282 fn round(&self) -> f32 { round(*self) }
284 /// The integer part of the number (rounds towards `0.0`)
286 fn trunc(&self) -> f32 { trunc(*self) }
288 /// The fractional part of the number, satisfying:
292 /// assert!(x == x.trunc() + x.fract())
295 fn fract(&self) -> f32 { *self - self.trunc() }
298 impl Bounded for f32 {
300 fn min_value() -> f32 { 1.17549435e-38 }
303 fn max_value() -> f32 { 3.40282347e+38 }
306 impl Primitive for f32 {}
310 fn max(self, other: f32) -> f32 {
311 unsafe { cmath::c_float::fmax(self, other) }
315 fn min(self, other: f32) -> f32 {
316 unsafe { cmath::c_float::fmin(self, other) }
320 fn nan() -> f32 { 0.0 / 0.0 }
323 fn infinity() -> f32 { 1.0 / 0.0 }
326 fn neg_infinity() -> f32 { -1.0 / 0.0 }
329 fn neg_zero() -> f32 { -0.0 }
331 /// Returns `true` if the number is NaN
333 fn is_nan(&self) -> bool { *self != *self }
335 /// Returns `true` if the number is infinite
337 fn is_infinite(&self) -> bool {
338 *self == Float::infinity() || *self == Float::neg_infinity()
341 /// Returns `true` if the number is neither infinite or NaN
343 fn is_finite(&self) -> bool {
344 !(self.is_nan() || self.is_infinite())
347 /// Returns `true` if the number is neither zero, infinite, subnormal or NaN
349 fn is_normal(&self) -> bool {
350 self.classify() == FPNormal
353 /// Returns the floating point category of the number. If only one property is going to
354 /// be tested, it is generally faster to use the specific predicate instead.
355 fn classify(&self) -> FPCategory {
356 static EXP_MASK: u32 = 0x7f800000;
357 static MAN_MASK: u32 = 0x007fffff;
359 let bits: u32 = unsafe {::cast::transmute(*self)};
360 match (bits & MAN_MASK, bits & EXP_MASK) {
362 (_, 0) => FPSubnormal,
363 (0, EXP_MASK) => FPInfinite,
364 (_, EXP_MASK) => FPNaN,
370 fn mantissa_digits(_: Option<f32>) -> uint { 24 }
373 fn digits(_: Option<f32>) -> uint { 6 }
376 fn epsilon() -> f32 { 1.19209290e-07 }
379 fn min_exp(_: Option<f32>) -> int { -125 }
382 fn max_exp(_: Option<f32>) -> int { 128 }
385 fn min_10_exp(_: Option<f32>) -> int { -37 }
388 fn max_10_exp(_: Option<f32>) -> int { 38 }
390 /// Constructs a floating point number by multiplying `x` by 2 raised to the power of `exp`
392 fn ldexp(x: f32, exp: int) -> f32 {
393 ldexp(x, exp as c_int)
396 /// Breaks the number into a normalized fraction and a base-2 exponent, satisfying:
398 /// - `self = x * pow(2, exp)`
399 /// - `0.5 <= abs(x) < 1.0`
401 fn frexp(&self) -> (f32, int) {
403 let x = frexp(*self, &mut exp);
407 /// Returns the exponential of the number, minus `1`, in a way that is accurate
408 /// even if the number is close to zero
410 fn exp_m1(&self) -> f32 { exp_m1(*self) }
412 /// Returns the natural logarithm of the number plus `1` (`ln(1+n)`) more accurately
413 /// than if the operations were performed separately
415 fn ln_1p(&self) -> f32 { ln_1p(*self) }
417 /// Fused multiply-add. Computes `(self * a) + b` with only one rounding error. This
418 /// produces a more accurate result with better performance than a separate multiplication
419 /// operation followed by an add.
421 fn mul_add(&self, a: f32, b: f32) -> f32 {
425 /// Returns the next representable floating-point value in the direction of `other`
427 fn next_after(&self, other: f32) -> f32 {
428 next_after(*self, other)
431 /// Returns the mantissa, exponent and sign as integers.
432 fn integer_decode(&self) -> (u64, i16, i8) {
433 let bits: u32 = unsafe {
434 ::cast::transmute(*self)
436 let sign: i8 = if bits >> 31 == 0 { 1 } else { -1 };
437 let mut exponent: i16 = ((bits >> 23) & 0xff) as i16;
438 let mantissa = if exponent == 0 {
439 (bits & 0x7fffff) << 1
441 (bits & 0x7fffff) | 0x800000
443 // Exponent bias + mantissa shift
444 exponent -= 127 + 23;
445 (mantissa as u64, exponent, sign)
448 /// Archimedes' constant
450 fn pi() -> f32 { 3.14159265358979323846264338327950288 }
454 fn two_pi() -> f32 { 6.28318530717958647692528676655900576 }
458 fn frac_pi_2() -> f32 { 1.57079632679489661923132169163975144 }
462 fn frac_pi_3() -> f32 { 1.04719755119659774615421446109316763 }
466 fn frac_pi_4() -> f32 { 0.785398163397448309615660845819875721 }
470 fn frac_pi_6() -> f32 { 0.52359877559829887307710723054658381 }
474 fn frac_pi_8() -> f32 { 0.39269908169872415480783042290993786 }
478 fn frac_1_pi() -> f32 { 0.318309886183790671537767526745028724 }
482 fn frac_2_pi() -> f32 { 0.636619772367581343075535053490057448 }
486 fn frac_2_sqrtpi() -> f32 { 1.12837916709551257389615890312154517 }
490 fn sqrt2() -> f32 { 1.41421356237309504880168872420969808 }
494 fn frac_1_sqrt2() -> f32 { 0.707106781186547524400844362104849039 }
498 fn e() -> f32 { 2.71828182845904523536028747135266250 }
502 fn log2_e() -> f32 { 1.44269504088896340735992468100189214 }
506 fn log10_e() -> f32 { 0.434294481903251827651128918916605082 }
510 fn ln_2() -> f32 { 0.693147180559945309417232121458176568 }
514 fn ln_10() -> f32 { 2.30258509299404568401799145468436421 }
516 /// The reciprocal (multiplicative inverse) of the number
518 fn recip(&self) -> f32 { 1.0 / *self }
521 fn powf(&self, n: &f32) -> f32 { pow(*self, *n) }
524 fn sqrt(&self) -> f32 { sqrt(*self) }
527 fn rsqrt(&self) -> f32 { self.sqrt().recip() }
530 fn cbrt(&self) -> f32 { cbrt(*self) }
533 fn hypot(&self, other: &f32) -> f32 { hypot(*self, *other) }
536 fn sin(&self) -> f32 { sin(*self) }
539 fn cos(&self) -> f32 { cos(*self) }
542 fn tan(&self) -> f32 { tan(*self) }
545 fn asin(&self) -> f32 { asin(*self) }
548 fn acos(&self) -> f32 { acos(*self) }
551 fn atan(&self) -> f32 { atan(*self) }
554 fn atan2(&self, other: &f32) -> f32 { atan2(*self, *other) }
556 /// Simultaneously computes the sine and cosine of the number
558 fn sin_cos(&self) -> (f32, f32) {
559 (self.sin(), self.cos())
562 /// Returns the exponential of the number
564 fn exp(&self) -> f32 { exp(*self) }
566 /// Returns 2 raised to the power of the number
568 fn exp2(&self) -> f32 { exp2(*self) }
570 /// Returns the natural logarithm of the number
572 fn ln(&self) -> f32 { ln(*self) }
574 /// Returns the logarithm of the number with respect to an arbitrary base
576 fn log(&self, base: &f32) -> f32 { self.ln() / base.ln() }
578 /// Returns the base 2 logarithm of the number
580 fn log2(&self) -> f32 { log2(*self) }
582 /// Returns the base 10 logarithm of the number
584 fn log10(&self) -> f32 { log10(*self) }
587 fn sinh(&self) -> f32 { sinh(*self) }
590 fn cosh(&self) -> f32 { cosh(*self) }
593 fn tanh(&self) -> f32 { tanh(*self) }
595 /// Inverse hyperbolic sine
599 /// - on success, the inverse hyperbolic sine of `self` will be returned
600 /// - `self` if `self` is `0.0`, `-0.0`, `INFINITY`, or `NEG_INFINITY`
601 /// - `NAN` if `self` is `NAN`
603 fn asinh(&self) -> f32 {
605 NEG_INFINITY => NEG_INFINITY,
606 x => (x + ((x * x) + 1.0).sqrt()).ln(),
610 /// Inverse hyperbolic cosine
614 /// - on success, the inverse hyperbolic cosine of `self` will be returned
615 /// - `INFINITY` if `self` is `INFINITY`
616 /// - `NAN` if `self` is `NAN` or `self < 1.0` (including `NEG_INFINITY`)
618 fn acosh(&self) -> f32 {
620 x if x < 1.0 => Float::nan(),
621 x => (x + ((x * x) - 1.0).sqrt()).ln(),
625 /// Inverse hyperbolic tangent
629 /// - on success, the inverse hyperbolic tangent of `self` will be returned
630 /// - `self` if `self` is `0.0` or `-0.0`
631 /// - `INFINITY` if `self` is `1.0`
632 /// - `NEG_INFINITY` if `self` is `-1.0`
633 /// - `NAN` if the `self` is `NAN` or outside the domain of `-1.0 <= self <= 1.0`
634 /// (including `INFINITY` and `NEG_INFINITY`)
636 fn atanh(&self) -> f32 {
637 0.5 * ((2.0 * *self) / (1.0 - *self)).ln_1p()
640 /// Converts to degrees, assuming the number is in radians
642 fn to_degrees(&self) -> f32 { *self * (180.0f32 / Float::pi()) }
644 /// Converts to radians, assuming the number is in degrees
646 fn to_radians(&self) -> f32 {
647 let value: f32 = Float::pi();
648 *self * (value / 180.0f32)
653 // Section: String Conversions
656 /// Converts a float to a string
660 /// * num - The float value
662 pub fn to_str(num: f32) -> ~str {
663 let (r, _) = strconv::float_to_str_common(
664 num, 10u, true, strconv::SignNeg, strconv::DigAll, strconv::ExpNone, false);
668 /// Converts a float to a string in hexadecimal format
672 /// * num - The float value
674 pub fn to_str_hex(num: f32) -> ~str {
675 let (r, _) = strconv::float_to_str_common(
676 num, 16u, true, strconv::SignNeg, strconv::DigAll, strconv::ExpNone, false);
680 /// Converts a float to a string in a given radix, and a flag indicating
681 /// whether it's a special value
685 /// * num - The float value
686 /// * radix - The base to use
688 pub fn to_str_radix_special(num: f32, rdx: uint) -> (~str, bool) {
689 strconv::float_to_str_common(num, rdx, true,
690 strconv::SignNeg, strconv::DigAll, strconv::ExpNone, false)
693 /// Converts a float to a string with exactly the number of
694 /// provided significant digits
698 /// * num - The float value
699 /// * digits - The number of significant digits
701 pub fn to_str_exact(num: f32, dig: uint) -> ~str {
702 let (r, _) = strconv::float_to_str_common(
703 num, 10u, true, strconv::SignNeg, strconv::DigExact(dig), strconv::ExpNone, false);
707 /// Converts a float to a string with a maximum number of
708 /// significant digits
712 /// * num - The float value
713 /// * digits - The number of significant digits
715 pub fn to_str_digits(num: f32, dig: uint) -> ~str {
716 let (r, _) = strconv::float_to_str_common(
717 num, 10u, true, strconv::SignNeg, strconv::DigMax(dig), strconv::ExpNone, false);
721 /// Converts a float to a string using the exponential notation with exactly the number of
722 /// provided digits after the decimal point in the significand
726 /// * num - The float value
727 /// * digits - The number of digits after the decimal point
728 /// * upper - Use `E` instead of `e` for the exponent sign
730 pub fn to_str_exp_exact(num: f32, dig: uint, upper: bool) -> ~str {
731 let (r, _) = strconv::float_to_str_common(
732 num, 10u, true, strconv::SignNeg, strconv::DigExact(dig), strconv::ExpDec, upper);
736 /// Converts a float to a string using the exponential notation with the maximum number of
737 /// digits after the decimal point in the significand
741 /// * num - The float value
742 /// * digits - The number of digits after the decimal point
743 /// * upper - Use `E` instead of `e` for the exponent sign
745 pub fn to_str_exp_digits(num: f32, dig: uint, upper: bool) -> ~str {
746 let (r, _) = strconv::float_to_str_common(
747 num, 10u, true, strconv::SignNeg, strconv::DigMax(dig), strconv::ExpDec, upper);
751 impl num::ToStrRadix for f32 {
752 /// Converts a float to a string in a given radix
756 /// * num - The float value
757 /// * radix - The base to use
761 /// Fails if called on a special value like `inf`, `-inf` or `NaN` due to
762 /// possible misinterpretation of the result at higher bases. If those values
763 /// are expected, use `to_str_radix_special()` instead.
765 fn to_str_radix(&self, rdx: uint) -> ~str {
766 let (r, special) = strconv::float_to_str_common(
767 *self, rdx, true, strconv::SignNeg, strconv::DigAll, strconv::ExpNone, false);
768 if special { fail!("number has a special value, \
769 try to_str_radix_special() if those are expected") }
774 /// Convert a string in base 16 to a float.
775 /// Accepts an optional binary exponent.
777 /// This function accepts strings such as
780 /// * '+a4.fe', equivalent to 'a4.fe'
782 /// * '2b.aP128', or equivalently, '2b.ap128'
784 /// * '.' (understood as 0)
786 /// * '.c', or, equivalently, '0.c'
787 /// * '+inf', 'inf', '-inf', 'NaN'
789 /// Leading and trailing whitespace represent an error.
797 /// `None` if the string did not represent a valid number. Otherwise,
798 /// `Some(n)` where `n` is the floating-point number represented by `[num]`.
800 pub fn from_str_hex(num: &str) -> Option<f32> {
801 strconv::from_str_common(num, 16u, true, true, true,
802 strconv::ExpBin, false, false)
805 impl FromStr for f32 {
806 /// Convert a string in base 10 to a float.
807 /// Accepts an optional decimal exponent.
809 /// This function accepts strings such as
812 /// * '+3.14', equivalent to '3.14'
814 /// * '2.5E10', or equivalently, '2.5e10'
816 /// * '.' (understood as 0)
818 /// * '.5', or, equivalently, '0.5'
819 /// * '+inf', 'inf', '-inf', 'NaN'
821 /// Leading and trailing whitespace represent an error.
829 /// `None` if the string did not represent a valid number. Otherwise,
830 /// `Some(n)` where `n` is the floating-point number represented by `num`.
832 fn from_str(val: &str) -> Option<f32> {
833 strconv::from_str_common(val, 10u, true, true, true,
834 strconv::ExpDec, false, false)
838 impl num::FromStrRadix for f32 {
839 /// Convert a string in a given base to a float.
841 /// Due to possible conflicts, this function does **not** accept
842 /// the special values `inf`, `-inf`, `+inf` and `NaN`, **nor**
843 /// does it recognize exponents of any kind.
845 /// Leading and trailing whitespace represent an error.
850 /// * radix - The base to use. Must lie in the range [2 .. 36]
854 /// `None` if the string did not represent a valid number. Otherwise,
855 /// `Some(n)` where `n` is the floating-point number represented by `num`.
857 fn from_str_radix(val: &str, rdx: uint) -> Option<f32> {
858 strconv::from_str_common(val, rdx, true, true, false,
859 strconv::ExpNone, false, false)
871 assert_eq!(NAN.min(2.0), 2.0);
872 assert_eq!(2.0f32.min(NAN), 2.0);
877 assert_eq!(NAN.max(2.0), 2.0);
878 assert_eq!(2.0f32.max(NAN), 2.0);
883 num::test_num(10f32, 2f32);
888 assert_approx_eq!(1.0f32.floor(), 1.0f32);
889 assert_approx_eq!(1.3f32.floor(), 1.0f32);
890 assert_approx_eq!(1.5f32.floor(), 1.0f32);
891 assert_approx_eq!(1.7f32.floor(), 1.0f32);
892 assert_approx_eq!(0.0f32.floor(), 0.0f32);
893 assert_approx_eq!((-0.0f32).floor(), -0.0f32);
894 assert_approx_eq!((-1.0f32).floor(), -1.0f32);
895 assert_approx_eq!((-1.3f32).floor(), -2.0f32);
896 assert_approx_eq!((-1.5f32).floor(), -2.0f32);
897 assert_approx_eq!((-1.7f32).floor(), -2.0f32);
902 assert_approx_eq!(1.0f32.ceil(), 1.0f32);
903 assert_approx_eq!(1.3f32.ceil(), 2.0f32);
904 assert_approx_eq!(1.5f32.ceil(), 2.0f32);
905 assert_approx_eq!(1.7f32.ceil(), 2.0f32);
906 assert_approx_eq!(0.0f32.ceil(), 0.0f32);
907 assert_approx_eq!((-0.0f32).ceil(), -0.0f32);
908 assert_approx_eq!((-1.0f32).ceil(), -1.0f32);
909 assert_approx_eq!((-1.3f32).ceil(), -1.0f32);
910 assert_approx_eq!((-1.5f32).ceil(), -1.0f32);
911 assert_approx_eq!((-1.7f32).ceil(), -1.0f32);
916 assert_approx_eq!(1.0f32.round(), 1.0f32);
917 assert_approx_eq!(1.3f32.round(), 1.0f32);
918 assert_approx_eq!(1.5f32.round(), 2.0f32);
919 assert_approx_eq!(1.7f32.round(), 2.0f32);
920 assert_approx_eq!(0.0f32.round(), 0.0f32);
921 assert_approx_eq!((-0.0f32).round(), -0.0f32);
922 assert_approx_eq!((-1.0f32).round(), -1.0f32);
923 assert_approx_eq!((-1.3f32).round(), -1.0f32);
924 assert_approx_eq!((-1.5f32).round(), -2.0f32);
925 assert_approx_eq!((-1.7f32).round(), -2.0f32);
930 assert_approx_eq!(1.0f32.trunc(), 1.0f32);
931 assert_approx_eq!(1.3f32.trunc(), 1.0f32);
932 assert_approx_eq!(1.5f32.trunc(), 1.0f32);
933 assert_approx_eq!(1.7f32.trunc(), 1.0f32);
934 assert_approx_eq!(0.0f32.trunc(), 0.0f32);
935 assert_approx_eq!((-0.0f32).trunc(), -0.0f32);
936 assert_approx_eq!((-1.0f32).trunc(), -1.0f32);
937 assert_approx_eq!((-1.3f32).trunc(), -1.0f32);
938 assert_approx_eq!((-1.5f32).trunc(), -1.0f32);
939 assert_approx_eq!((-1.7f32).trunc(), -1.0f32);
944 assert_approx_eq!(1.0f32.fract(), 0.0f32);
945 assert_approx_eq!(1.3f32.fract(), 0.3f32);
946 assert_approx_eq!(1.5f32.fract(), 0.5f32);
947 assert_approx_eq!(1.7f32.fract(), 0.7f32);
948 assert_approx_eq!(0.0f32.fract(), 0.0f32);
949 assert_approx_eq!((-0.0f32).fract(), -0.0f32);
950 assert_approx_eq!((-1.0f32).fract(), -0.0f32);
951 assert_approx_eq!((-1.3f32).fract(), -0.3f32);
952 assert_approx_eq!((-1.5f32).fract(), -0.5f32);
953 assert_approx_eq!((-1.7f32).fract(), -0.7f32);
958 assert_eq!(0.0f32.asinh(), 0.0f32);
959 assert_eq!((-0.0f32).asinh(), -0.0f32);
961 let inf: f32 = Float::infinity();
962 let neg_inf: f32 = Float::neg_infinity();
963 let nan: f32 = Float::nan();
964 assert_eq!(inf.asinh(), inf);
965 assert_eq!(neg_inf.asinh(), neg_inf);
966 assert!(nan.asinh().is_nan());
967 assert_approx_eq!(2.0f32.asinh(), 1.443635475178810342493276740273105f32);
968 assert_approx_eq!((-2.0f32).asinh(), -1.443635475178810342493276740273105f32);
973 assert_eq!(1.0f32.acosh(), 0.0f32);
974 assert!(0.999f32.acosh().is_nan());
976 let inf: f32 = Float::infinity();
977 let neg_inf: f32 = Float::neg_infinity();
978 let nan: f32 = Float::nan();
979 assert_eq!(inf.acosh(), inf);
980 assert!(neg_inf.acosh().is_nan());
981 assert!(nan.acosh().is_nan());
982 assert_approx_eq!(2.0f32.acosh(), 1.31695789692481670862504634730796844f32);
983 assert_approx_eq!(3.0f32.acosh(), 1.76274717403908605046521864995958461f32);
988 assert_eq!(0.0f32.atanh(), 0.0f32);
989 assert_eq!((-0.0f32).atanh(), -0.0f32);
991 let inf32: f32 = Float::infinity();
992 let neg_inf32: f32 = Float::neg_infinity();
993 assert_eq!(1.0f32.atanh(), inf32);
994 assert_eq!((-1.0f32).atanh(), neg_inf32);
996 assert!(2f64.atanh().atanh().is_nan());
997 assert!((-2f64).atanh().atanh().is_nan());
999 let inf64: f32 = Float::infinity();
1000 let neg_inf64: f32 = Float::neg_infinity();
1001 let nan32: f32 = Float::nan();
1002 assert!(inf64.atanh().is_nan());
1003 assert!(neg_inf64.atanh().is_nan());
1004 assert!(nan32.atanh().is_nan());
1006 assert_approx_eq!(0.5f32.atanh(), 0.54930614433405484569762261846126285f32);
1007 assert_approx_eq!((-0.5f32).atanh(), -0.54930614433405484569762261846126285f32);
1011 fn test_real_consts() {
1012 let pi: f32 = Float::pi();
1013 let two_pi: f32 = Float::two_pi();
1014 let frac_pi_2: f32 = Float::frac_pi_2();
1015 let frac_pi_3: f32 = Float::frac_pi_3();
1016 let frac_pi_4: f32 = Float::frac_pi_4();
1017 let frac_pi_6: f32 = Float::frac_pi_6();
1018 let frac_pi_8: f32 = Float::frac_pi_8();
1019 let frac_1_pi: f32 = Float::frac_1_pi();
1020 let frac_2_pi: f32 = Float::frac_2_pi();
1021 let frac_2_sqrtpi: f32 = Float::frac_2_sqrtpi();
1022 let sqrt2: f32 = Float::sqrt2();
1023 let frac_1_sqrt2: f32 = Float::frac_1_sqrt2();
1024 let e: f32 = Float::e();
1025 let log2_e: f32 = Float::log2_e();
1026 let log10_e: f32 = Float::log10_e();
1027 let ln_2: f32 = Float::ln_2();
1028 let ln_10: f32 = Float::ln_10();
1030 assert_approx_eq!(two_pi, 2f32 * pi);
1031 assert_approx_eq!(frac_pi_2, pi / 2f32);
1032 assert_approx_eq!(frac_pi_3, pi / 3f32);
1033 assert_approx_eq!(frac_pi_4, pi / 4f32);
1034 assert_approx_eq!(frac_pi_6, pi / 6f32);
1035 assert_approx_eq!(frac_pi_8, pi / 8f32);
1036 assert_approx_eq!(frac_1_pi, 1f32 / pi);
1037 assert_approx_eq!(frac_2_pi, 2f32 / pi);
1038 assert_approx_eq!(frac_2_sqrtpi, 2f32 / pi.sqrt());
1039 assert_approx_eq!(sqrt2, 2f32.sqrt());
1040 assert_approx_eq!(frac_1_sqrt2, 1f32 / 2f32.sqrt());
1041 assert_approx_eq!(log2_e, e.log2());
1042 assert_approx_eq!(log10_e, e.log10());
1043 assert_approx_eq!(ln_2, 2f32.ln());
1044 assert_approx_eq!(ln_10, 10f32.ln());
1049 assert_eq!(INFINITY.abs(), INFINITY);
1050 assert_eq!(1f32.abs(), 1f32);
1051 assert_eq!(0f32.abs(), 0f32);
1052 assert_eq!((-0f32).abs(), 0f32);
1053 assert_eq!((-1f32).abs(), 1f32);
1054 assert_eq!(NEG_INFINITY.abs(), INFINITY);
1055 assert_eq!((1f32/NEG_INFINITY).abs(), 0f32);
1056 assert!(NAN.abs().is_nan());
1061 assert_eq!((-1f32).abs_sub(&1f32), 0f32);
1062 assert_eq!(1f32.abs_sub(&1f32), 0f32);
1063 assert_eq!(1f32.abs_sub(&0f32), 1f32);
1064 assert_eq!(1f32.abs_sub(&-1f32), 2f32);
1065 assert_eq!(NEG_INFINITY.abs_sub(&0f32), 0f32);
1066 assert_eq!(INFINITY.abs_sub(&1f32), INFINITY);
1067 assert_eq!(0f32.abs_sub(&NEG_INFINITY), INFINITY);
1068 assert_eq!(0f32.abs_sub(&INFINITY), 0f32);
1071 #[test] #[ignore(cfg(windows))] // FIXME #8663
1072 fn test_abs_sub_nowin() {
1073 assert!(NAN.abs_sub(&-1f32).is_nan());
1074 assert!(1f32.abs_sub(&NAN).is_nan());
1079 assert_eq!(INFINITY.signum(), 1f32);
1080 assert_eq!(1f32.signum(), 1f32);
1081 assert_eq!(0f32.signum(), 1f32);
1082 assert_eq!((-0f32).signum(), -1f32);
1083 assert_eq!((-1f32).signum(), -1f32);
1084 assert_eq!(NEG_INFINITY.signum(), -1f32);
1085 assert_eq!((1f32/NEG_INFINITY).signum(), -1f32);
1086 assert!(NAN.signum().is_nan());
1090 fn test_is_positive() {
1091 assert!(INFINITY.is_positive());
1092 assert!(1f32.is_positive());
1093 assert!(0f32.is_positive());
1094 assert!(!(-0f32).is_positive());
1095 assert!(!(-1f32).is_positive());
1096 assert!(!NEG_INFINITY.is_positive());
1097 assert!(!(1f32/NEG_INFINITY).is_positive());
1098 assert!(!NAN.is_positive());
1102 fn test_is_negative() {
1103 assert!(!INFINITY.is_negative());
1104 assert!(!1f32.is_negative());
1105 assert!(!0f32.is_negative());
1106 assert!((-0f32).is_negative());
1107 assert!((-1f32).is_negative());
1108 assert!(NEG_INFINITY.is_negative());
1109 assert!((1f32/NEG_INFINITY).is_negative());
1110 assert!(!NAN.is_negative());
1114 fn test_is_normal() {
1115 let nan: f32 = Float::nan();
1116 let inf: f32 = Float::infinity();
1117 let neg_inf: f32 = Float::neg_infinity();
1118 let zero: f32 = Zero::zero();
1119 let neg_zero: f32 = Float::neg_zero();
1120 assert!(!nan.is_normal());
1121 assert!(!inf.is_normal());
1122 assert!(!neg_inf.is_normal());
1123 assert!(!zero.is_normal());
1124 assert!(!neg_zero.is_normal());
1125 assert!(1f32.is_normal());
1126 assert!(1e-37f32.is_normal());
1127 assert!(!1e-38f32.is_normal());
1131 fn test_classify() {
1132 let nan: f32 = Float::nan();
1133 let inf: f32 = Float::infinity();
1134 let neg_inf: f32 = Float::neg_infinity();
1135 let zero: f32 = Zero::zero();
1136 let neg_zero: f32 = Float::neg_zero();
1137 assert_eq!(nan.classify(), FPNaN);
1138 assert_eq!(inf.classify(), FPInfinite);
1139 assert_eq!(neg_inf.classify(), FPInfinite);
1140 assert_eq!(zero.classify(), FPZero);
1141 assert_eq!(neg_zero.classify(), FPZero);
1142 assert_eq!(1f32.classify(), FPNormal);
1143 assert_eq!(1e-37f32.classify(), FPNormal);
1144 assert_eq!(1e-38f32.classify(), FPSubnormal);
1149 // We have to use from_str until base-2 exponents
1150 // are supported in floating-point literals
1151 let f1: f32 = from_str_hex("1p-123").unwrap();
1152 let f2: f32 = from_str_hex("1p-111").unwrap();
1153 assert_eq!(Float::ldexp(1f32, -123), f1);
1154 assert_eq!(Float::ldexp(1f32, -111), f2);
1156 assert_eq!(Float::ldexp(0f32, -123), 0f32);
1157 assert_eq!(Float::ldexp(-0f32, -123), -0f32);
1159 let inf: f32 = Float::infinity();
1160 let neg_inf: f32 = Float::neg_infinity();
1161 let nan: f32 = Float::nan();
1162 assert_eq!(Float::ldexp(inf, -123), inf);
1163 assert_eq!(Float::ldexp(neg_inf, -123), neg_inf);
1164 assert!(Float::ldexp(nan, -123).is_nan());
1169 // We have to use from_str until base-2 exponents
1170 // are supported in floating-point literals
1171 let f1: f32 = from_str_hex("1p-123").unwrap();
1172 let f2: f32 = from_str_hex("1p-111").unwrap();
1173 let (x1, exp1) = f1.frexp();
1174 let (x2, exp2) = f2.frexp();
1175 assert_eq!((x1, exp1), (0.5f32, -122));
1176 assert_eq!((x2, exp2), (0.5f32, -110));
1177 assert_eq!(Float::ldexp(x1, exp1), f1);
1178 assert_eq!(Float::ldexp(x2, exp2), f2);
1180 assert_eq!(0f32.frexp(), (0f32, 0));
1181 assert_eq!((-0f32).frexp(), (-0f32, 0));
1184 #[test] #[ignore(cfg(windows))] // FIXME #8755
1185 fn test_frexp_nowin() {
1186 let inf: f32 = Float::infinity();
1187 let neg_inf: f32 = Float::neg_infinity();
1188 let nan: f32 = Float::nan();
1189 assert_eq!(match inf.frexp() { (x, _) => x }, inf)
1190 assert_eq!(match neg_inf.frexp() { (x, _) => x }, neg_inf)
1191 assert!(match nan.frexp() { (x, _) => x.is_nan() })
1195 fn test_integer_decode() {
1196 assert_eq!(3.14159265359f32.integer_decode(), (13176795u64, -22i16, 1i8));
1197 assert_eq!((-8573.5918555f32).integer_decode(), (8779358u64, -10i16, -1i8));
1198 assert_eq!(2f32.powf(&100.0).integer_decode(), (8388608u64, 77i16, 1i8));
1199 assert_eq!(0f32.integer_decode(), (0u64, -150i16, 1i8));
1200 assert_eq!((-0f32).integer_decode(), (0u64, -150i16, -1i8));
1201 assert_eq!(INFINITY.integer_decode(), (8388608u64, 105i16, 1i8));
1202 assert_eq!(NEG_INFINITY.integer_decode(), (8388608u64, 105i16, -1i8));
1203 assert_eq!(NAN.integer_decode(), (12582912u64, 105i16, 1i8));